Acenes are an exciting class of compounds that have been intensely studied during the past decade. Their alluring optoelectronic properties suggest great potential as the conducting organic material in a variety of device applications such as organic light-emitting diodes (OLEDs), field-effect transistors (OFETs), and solar cells. Pentacene (compound 1) and its derivatives (e.g., compound 2) have received the vast amount of attention as this molecule has been hailed as the benchmark for thin film devices. Unfortunately, pentacene readily oxidizes to its respective quinone in aerobic conditions and reacts with itself to afford a butterfly dimer. The driving force for both reactions is the formation of two aromatic naphthalene units which ultimately disrupts overall conjugation and thus leads to poor device performance. While ethynylogation as in compound 2 or substitution with thioethers will in general slow degradation, these processes are not completely suppressed.
In addition, in the solid state pentacene packs in an edge-to-face or ‘Herring Bone’ conformation, which eliminates the possibility of intermolecular π-orbital interactions. Such interactions are crucial for efficient electron transfer, an important characteristic for improving device functionality and performance.
Hence, there is high demand for pentacenelike organic molecules that do not suffer from the disadvantages of pentacene, and offer greater stability to air and light.